DESCRIPTION (adapted from investigator's abstract and/or aims): The most cursory clinical screening of upper GI disorders presently requires hospitalization and expensive invasive tests. This project is expected to ultimately lead to a compact noninvasive system for evaluating gastric motor function in man. Areas of application include clinical/office use and research in space medicine. A technique for studying gastric motility in zero/micro gravity environments would shed light on the pathophysiology of space motion sickness and similar disorders. The applicant aims to develop a reliable and accurate method of evaluating gastric function noninvasively. This will be achieved through noninvasive measurements of the main indicators of gastric motor function, namely: electrical and contractile activities and emptying. If the technique is to accurately detect gastric dysfunction, problems with the "state-of-the-art" methods of recording these activities must be resolved (noise, poor specificity and invasiveness). Therefore, (1) modeling and computer simulation of gastric electrical activity in the diseased state will be employed to design a surface electrode array that accurately detects gastric electrical abnormalities. The results will be validated in human studies. (2) Electrical impedance measurements in the epigastric region of the torso, will be employed to monitor gastric contractions and emptying. (3) These indicators will be combined to evaluate gastric function in human volunteers and the results will be compared with those from established invasive gastric emptying and intraluminal manometric studies. The same system will be employed in double blind studies of patients with gastric disease.